Refrigeration



March 14, 1939. c. G. MUNTERS REFRIGERATION Filed March 31, 5sheets-sheet 1 I IIIIIIIIIIIIL INVENTOR .7 ATTORNEY March 14, 1939.

c. G. MUNTERS REFRIGERAT ION Filed March 5l, 1934 5 sheets-sheet 2 March14, 1939. c. G.' MuNTx-:Rs

REFRIGERATION Filed March 3l, 1954 5 Sheets-Sheet 5 /l NVENTOR 147 M WJATTO RNEY

March 14, 1939. C. G, MUNTERS 2,150,181

REFRIGERATION Filed March 5l, 1954 5 Sheets-Sheet 4 w /l 68 l 6?INVENTOR March 14, 1939. Cl G. MUNTERS 2,150,181

REFRIGERA'TION Filed March 3l, 1934 5 Sheets-Sheet 5 i7 O I I INVENToRPatented Mar. 14, 192.9v

UNITED STATES 2,150,181 REFRJGERATION Carl Georg Munters, Stockholm,Sweden, assignor to Aktiebolaget Termisk Isolation, Stockholm, Sweden, acorporationl of Sweden Application March 31, 1934, Serial No. '718,392

In Sweden November 16, 1933 My invention relates to refrigeration andmore particularly to the conservation of cold produced by arefrigerating apparatus or the like.

One of the objects of my invention is to provide a refrigerator having alight, sturdy insulation.

Another object of my invention is to utilize the cooling effect of theprimary cold producer to prevent condensation in insulation. In thisconnection, I produce a circulationl of air in the insulation in amanner as hereinafter set forth.

The nature and advantages of my invention will be understood from thefollowing description taken' in conjunction with the accompanyingdrawings forming part of this specification, and of which:

Fig. 1 is a vertical cross-sectional view of a refrigerator embodyingthe invention, and is taken on the line I-I, of Fig. 3;A

Fig. 2 is a view of part of the structure shown in Fig. l on largerscale;

Fig. 3 is a vertical cross-sectional view takenon the line 3-3 of Fig.l;

Fig. 4 is a horizontal sectional view taken on the line 4 4 of Fig. 3;

Fig. 5 is a horizontal sectional view taken on the line 5-5 of Fig. l;

Fig. 6 is a plan view of a sheet of cardboard before bending, formingpart of structure shown in other figures;

Fig. '1 shows another piece of cardboard;

Fig. 8 shows a modified form of the construction shown in Fig. 5; andFig. 9 shows a detail. The refrigerator includes a cabinet which inandhaving flanges II which are secured to a k frame member I2 as by screwsI3. Frame meme ber I2 may be made of wood. 'Ifhe lining I Il is made ofsheet steel and may be porcelained. It

vertical wall through which part of the refrigerating apparatus isinserted. The lining forms the border of the food space I5 of therefrigerator.

the frame member I2. The outer shell may be made up of a plurality ofplates welded or otherwise secured together. Angle irons I'I may beprovided at the corners to which the plates are secured. A refrigeratorapparatus compartment is formed back of sheet I6 by suitable plating.

Between the inner and outer shells III and I6 are spaced cardboardboxes. In the embodiment shown, threesuch boxes are provided. 'I'henumber may be more or less depending on the temcludes an inner shell orlining I0 open at the front is also provided with an opening I4 in itsback- An outer insulation Shen 'I6 is also secured to peraturediierential to be maintained between the food space I5 and thesurrounding atmosphere 0r space. The three boxes or containers aredesignated IB, I9 and 20. These boxes are similar and the description ofone will suffice. I

Box I8 is essentially a five-sided cardboard box open at the front oflthe cabinet having sheets 2I of aluminum foil pasted or otherwisedisposed on each side. Other material having bright surface for heatreection' may be used but the most readily obtainable at the presenttime is sheets of aluminum of, for example, 0.00'1 millimeter inthickness.

The box is formed from sheet cardboard and can be advantageously made upfrom pieces as shown in Figs. 6 and '1. A sheet of cardboard, which maybe, for example, of the kind having smooth outer sheets and anintermediate corrugated sheet, and having a thickness of, for example1/8 to 11g inch, is notched as shown in Fig. 6 and bent along the lines22, 23 and 24 to form three sides of the box. An opening 25 is cut inthe middle section to be in line with opening I4 of the liner andflanges 23 for this opening are formed by cutting on the lines 21 andfolding on the dotted lines 28.. Side flanges 30 are formed by bendingalong the dotted lines 29. Side pieces or panels 32 of cardboard arethen pasted to the flanges 30, thus forming the flve sided box. Flanges3| are provided at the open side of the box thus formed. These are bentover on the dotted lines 33.

On mounting the cardboard box in the cabinet. these anges 3l are securedto the frame member I2 as by nails 3l. Preferably strips 35 of cardboardare glued onto the frame member I2 and the flanges 3| glued or cementedonto the card# board strips 35 as well as secured by nails. It is alsopreferable to glue or cement pieces of paper or cloth over the meetingedges of pieces 32 and` flanges 30. The boxes are to be tight at theseedges andalso tight where secured to the frame member I2. When mounted,the flanges 23 are glued or cemented to a cardboard collar 31 aligningthe openings at the back of the cabinet for the refrigerating unit. Thecollar 31 is made tight with the liner as by being flanged at 38 landglued or cemented to the liner. Collar-31 is secured to the outer shellas by being flanged at 40 and pressed between the outer shell and a,wooden frame 4I by screws I2. Cement, glue -or other tightening meansmay also be here applied.

The sheets of. metal 1011 are pasted on veach j side of the cardboardboxes. No foil is, however, pasted on flanges 3| or 23.

The cardboard boxes with their bright metal surfaces are nested withineach other to provide air spaces 46, 41, 48 and 48. 'Ihese air spacesare tight against; leakage of air except for cer- 5 tain holeshereinafter specied. The boxes may be spaced a distance of, for example,2 to 2.5 centimeters (about 3A to 1 inch).

Sheets of aluminum foil 50 and 5I are also pasted or glued onto theouter surface of the liner I 0 'and the inner surface of the outer shellI6 respectively.

The refrlgerating apparatus includes an evaporator 52 mounted on a pipeor heat exchanger 53 passing through an insulated wall part 54 which tsinto the openings at the rear formed in the inner and outer sheets andthe cardboard boxes. The member 53 is connected to that partrefrigerating apparatus |53 which is outof the side the insulated foodspace. The type of refrigerating apparatus is immaterial.- It may be ofthe compression type or the absorption type with any desired form ofheat input, as for example a burner |54. Other sources of cold may alsobe used such as ice or solidied carbon dioxide. With certain types ofcold producers, the opening in the rear is not necessary. The type ofapparatus may be that shown in Pats. No. 1,609,- 334, 1,910,853 and2,037,782.

Where a removable wall section such as 54 is used, it may be made as aslab of cork .havingv an inside plate 55 and an outside plate 56. Toprovide tightness, a gasket 51 is mounted on an outturned ange 58 on theliner against which plate 55 bears and a gasket 59 is provided betweenplate 56 and the outer shell.

The door is constructed in similar manner. It includes an outer shell 60secured to a wooden frame member 6I. Awooden frame member 62 is ysecuredto member 6I. A sheet of metal foil 63 is glued or cemented to theinside surface of shell 60. A sheet of cardboard 64 with sheets of metalfoil on each side thereof is placed against frame member 6I which spacesit from member 60 by, for example, three fourths of an inch.

A box 65 is made with sides 66 which are nailed or glued, or both, tomember 62. 'I'his member is coated with metal foil except for thesideanges 66. One or more additional such boxes 61 may be inserted. Aninner door shell 68, coated with metal foil on the side toward box 61sets into a rubber gasket 69 and is held in place as by screws fastenedvinto member 62. Parts 62, 65 and 61 may be, for example, a separatesubfassembly.

Suitable tightening means such as a metal strip 88 fastened to the doorand bearing against a ber strip 89 fastened to member I2 may be'employedbetween the door and the outer shell I6. The spaces between the parallelcardboard pieces in 60 the door may be on the order of 1 inch. Lessspacing, as shown, may be used but obviously the Wider the spacing, theless the material for a given door width. This spacing is hereinaftermore fully discussed. d

For the purpose of preventing condensation within the insulation, Iprovide means for circulation of air. A pipe Ill is provided extendingthrough the closure or panel 54 affording direct communication betweenthe outer atmosphere 70 and the food space. In the embodiment shown,this pipe is of 5 millimeters inside diameter. In the lining I0 is ahole or port'1I somewhat above the bottom of the food space. This hole,in the embodiment shown is of 8.millimeters diameter., 75 In the centertop of boxhI is a 10 millimeter hole 12. In the bottom center of box I9is a 10 millimeter hole 13. In the bottom of box 20 to one side of thehole in box I9 is a 10 millimeter hole 15. The outer shell is similarlyapertured as at 16.

By means of these apertures, a very slow circulation of air is producedfrom the outside atmosphere through pipe 10 into the space I5, thencethrough hole 1I into space 46, thence through hole 'I2 into space 41,thencethrough hole 13 into space 48, and through holes 'I5 and 16 backto the outer atmosphere. The air passing into the space I5 is cooled tothe lowest temperature. 'Ihe cooling should be such that on subsequentflow through the spaces of the insulation, condensation does not occur.A natural circulation is set up in the aforesaid direction4 twice therecommended spacing without having serious convection currents in theintervening air spaces. The spacing can be, for example, 2 to 2.5centimeters, or 3A to 1 inch. At these spacings, convection currentswill take place Abetween the vertical walls but I have determined thatwith the insulation herein described, advantages are obtained which morethan offset losses due to the small convection movement of the air. Itis particularly difficult to build up a suitable structure for holdingunbacked metal foils in an irregular wall structure as in arefrigerator. The frames l conduct heat and are expensive if made so asto prevent losses in the frames. By using seifsupporting boxes, I avoidcorner frames and I avoid transverse conduction at the corners, and Ientirely avoid intermediate spacing members which would conduct heat.Furthermore I provide 'equal temperature spaces around the food spaceseparated from each other except at the front frame.V This makes itpossible to provide a slow, uniform air circulation throughout theinsulation. With separate overlapping packages, heat conducting pathsare formed and, to

lhave a proper circulation, connections between the packages would benecessary, which is complicated.

Condensation in insulation of a refrigerator is a difficult problem.Condensation takes place when air is cooled so that moistureprecipitates therefrom. It is therefore desirable that air does not flowfrom the atmosphere through the insulation to or toward the food space.To prevent this, I make use of a preponderance of weight between columnsof air to force circulation of air outwardly through the insulation sothat condensation cannot take place within the insulation. I conduct airinto the food space so that it is first coooled and moisture maytherefore deposit out in the food space. 'Ihus I ensure dry air passingthrough the insulation and prevent moisture which would corrode themetal surfaces and otherwise harm the insulation and detract from theinsulation properties. Since I use very few layers, it is important thatthey shall' not have a lm of water on them,

u and having a lower liquid sealed opening in a drip amarsi The doorspaces may `likewise be provided with means for ow of air outwardly fromthe food space although a door can readily be made tight with respect tothe outer atmosphere and forced air circulation isnot of such importanceas in the cabinet itself. As an example, a hole may be provided in plate88 at the level of hole 1 I a hole may be provided in member 61 at ahigh part thereof, a hole in member 65 at a low part thereof, a hole inmember 64 at a high part thereof, and a hole in the bottom of member 60.In some instances, natural leakage may be relied on instead of holes butI prefer definite lholes with the spaces otherwise air-tight so that apositive controlled circulation may be obtained. The holes should be ofsuillcient size to provide adequate circulation to prevent condensationbut so small as to prevent appreciable loss of cooling effect due to theflow.

-The aperture into the food space may advantageously be higherthan theaperture between the food space and space 46 so that a cold down-leg isassured and the supply of the air to the food space can advantageouslybe through the rear window adjacent the evaporator so that goodcoolingof the air is obtained.

However, the openings may be 4arranged kin la variety of ways so long asthe outward movement is assured. The holes should be arranged to give apreponderance of specic gravity of air column so that the flow isdirected from the inside to the outside. It is preferred to so arrangethe holes that there is movement of air all around the refrigeratedspace. By means of the nested box construction I am able to provide apath of ow of air which entirely encompasses the refrigerated space.

'I'he air need not circulate entirely through the insulation but maycirculate from the food space, downwardly in the first outer space,upwardly through a second outer space bf higher temperature and back tothe food space for drying by cooling.

'I'he hole 1| is preferably positioned so that water will noty enter thesame on washing out the interior of the refrigerator. It may be placed,as

shown, on a shelf supporting projection in thel liner.

Another door construction is shown in Fig. 8

in which cardboard boxes 80 and 8| are nailed and/or glued, togetherwith member 64, onto the frame member 8|. This door constructionincludes a Bakelite frame 82 and rubber gasketing I3. Long screws maypass through plate 68 and into member 6|. It will be seen that I providea light door construction which is easy to build.

It will be seerr that the amount of material necessary to handle formaking the insulation is small. Sheets of cardboard and aluminum foilcan be stored in small space and readily formed in the process ofmanufacture.

Fig. 9 shows a moisture separator which may be inserted in the aperture1i. It includes a casing 98 having bailles 9| therein and an end piece92 having a central opening. Bafiles 9| are apertured to provide atortuous path for gas and cut at their lower parts to allow separatedmoisture to flow into the food space I5. v

Instead of having the opening 15 in the bottom of box 20, this openingmay be higher up or at the.

top so that complete circulation takes place through all the air spaces.

The pipe 10 may be arranged to extenddownwardly for some distance withinthe food space pan and a branch connected to space l5 whereby the air iscooled and dehydrated due to the cooling source and lad directly intospace 46.

It will be noted that an important factor is that air shall not passinwardly through the insulation to or toward the food space. 'Iheoutside shell of the insulation can be made tight, but even in such caseit is advantageous to have a cold air column acting against the outsideshell to allow breathing of the insulation due to barometric variationsor otherwise without condensation and to guard against unintentionalleaks.

It will be understoodv that the invention is not limited to theembodiment disclosed and that many variations are ,possible within thescope and spirit of the invention.

What I claim is: 1. A refrigerator having a framework, an inner linerattached to said framework, an outer shell attached to said framework,and intermediate cent one of said boxes, said boxes being surfaced 2. Arefrigerator having an outer shell, an in ner liner spaced therefrom,said outer shelland said liner being open on a common vertical side toprovide a door opening, a plurality of nested, light, non-metallicself-sustaining box-like members between said shell and said liner,closure means between the liner and shell and members at said verticalside, .said members being appreciably spaced from each other and fromthe liner and from the outer shell, said members being surfaced withbright metallic layers and surrounding all walls of the liner wherebyintermediate spaces having both horizontal and vertical portions areformed between fthe liner and the outer shell, ,said liner having anopening in its lower part forming an air ow passage between the interiorspace of the liner and a first intermediate space and said membershaving additional openings at different elevations whereby aircirculation is produced due to difference of specific weight ofdifferent vertical air columns and air circulation is induced in thehorizontal portions of the intermediate spaces due to the verticalcolumns of different specific weight.

3. A refrigerator having an outer shell, an inner liner spacedtherefrom, said outer shell and said liner being open on a commonvertical side to provide a door opening, a plurality of nested, light,self-sustaining rigid cardboard box-like members between said shell ,andsaid liner, closure means between the liner and shell and members atsaidvertical side, said members being spaced from each other and from theliner and from the outer shell on the order of one half an inch to aninch, said members being surfaced with bright metallic layers andsurrounding all walls of the liner whereby intermediate spaces havingboth horizontal and vertical portions are formed between the liner andthe outer shell, said liner having an opening lin its lower part formingan air ow passage between the interior space of the liner and a firstintermediate space and said members having additional openings atdifferent elevations whereby air circulation is produced dug todifference of portions ofthe intermediate spaces due to the verticalcolumns of different specific weight.

4. A refrigerator having an outer shell, an inner liner spacedtherefrom, said outer shell and said liner being' open on a commonvertical side to provide a door opening, a plurality of nested light,non-metallic self-sustaining box-like members between said shell andsaid liner, closure means between the liner and shell and members atsaid vertical side, said members being appreciably spaced from eachother and from the liner and from the outer shell, said members beingsurfaced with bright metallic layers, said liner having an openingforming a communication between the interior space of the liner and afirst intermediate space and said members having additional aper.-turing whereby air circulation is produced due to diierence of specificweight of different vertical air columns.

5. A refrigerator having an outer shell, an inner liner spacedtherefrom, said outer shell and said liner being open on a commonvertical side to provide a door opening, a framework at the edges of andconnecting the outer shell and the liner, a plurality of nested, light,self-sustaining cardboard box-like members between said shell and saidliner attached at their edges to said framework, said members beingappreciably spaced from each other and from the liner and from the outershell, said members being surfaced with bright metallic layers andsurrounding all walls of the liner whereby intermediatey spaces havingboth horizontal and vertical portions are formed between the liner andthe outer shell, said liner having an opening in its lower part formingan air ow passage between the interior space of the liner and a rstintermediate space and atleast some of said members having openings atdifferent elevations whereby air circulationis produced due todifference of specific weight of different vertical air columns and aircirculation induced in the horizontal portions of the intermediatespaces due to the vertical columns of different specific weight.

6. Refrigerator cabinet construction comprising an outer shell, aplurality of self-sustaining boxlike structures nested one Within theother, said plurality of boxlike structures being formed of poor heatconducting material and mounted in the.

outer shell in spaced relation to the walls thereof, a liner inwardly ofthe innermost structure constructed to form a food storage compartment,certain of said structures having a surface of a nature to obstruct iiowof heat through the structure towards the center of the cabinet, andmeans for restricted air communication between the storage compartmentand spaces adjacent said boxlike sustaining and being surfaced withmetallic reflective material to hinder loss by radiation, and means forrestricted air communication between said compartment and space adjacentsaid insulating unit.

8. A device of the class described comprising inner and outer shells,insulating means between said shells comprising a plurality of preformedspaced self-sustaining boxlike structures of aluminum surfaced cardboardnested one within the other and means for restricted air circulation inspaces between the said boxlike structures.

9. Cabinet construction comprising a door frame, a self-sustaining heatflow obstructing insulating unit mounted on said door frame comprising aboxlike structure formed of non-metallic poor heat conducting materialand having a metallic heat reflecting surface.

10. Insulation comprising a plurality of preformed generally box shapedheat ow obstructing units nested in spaced relation and having walls ofself-sustaining non-metallic poor heat conducting material provided withmetallic heat reflecting surfaces.

11. Insulation for use with walls forming an enclosure to retard heatflow through the walls of said enclosure comprising a self-sustainingheat ow obstructing insulating unit in the form of a boxlike structurecomposed of non-metallic poor heat conducting material and having ametallic reecting surface.

12. A device of the character described comprising walls forming acompartment, means for insulating to retard heat flow through said wallscomprising a series of nested preformed insulating units about saidcompartment disposed in separated relation to provide intermediate airspaces, and means forproducing circulation of air outwardly from thecompartment between said nested units whereby moisture condensed withinsaid nested units will be carried outwardly to the atmosphere.

13. Refrigerator construction comprising walls forming a storagecompartment, spaced nested insulating units about said compartmentproviding air spaces, cooling means within said compartment, means forpermitting breathing between said compartment and said air spaces,whereby incoming air will be cooled due to the cooling means in saidcompartment and thereby reduced in moisture content and such dried airmay take up moisture as it flows in the air spaces provided by saidnested insulating units.

14. Refrigerator construction comprising walls forming a storagecompartment, spaced nested insulating umts about said compartmentproviding air spaces, cooling means within said com- I partment, meansfor permitting breathing between said compartment and said spaces,whereby incoming air will be cooled due to the cooling means in saidcompartment and thereby reduced in moisture content and such dried airmay take up moisture as it flows in the air spaces provided by saidnested insulating units, the construction being such that air ow is overa substantial portion of the insulation.

15. Refrlgerating construction comprising walls forming a storagecompartment, spaced nested insulating units about said compartment,cooling means within said compartment, means for admitting air directlyinto the compartment in the vicinity of the cooling means, and means fordischarging air from the compartment through said nested units in acircuitous path to take up moisture from said insulating units.

CARL GEORG MUNTERS.

